Toys R Us: Your child will get a birthday gift every year until he or she turns 10. Your kid will also get a birthday call from Geoffrey the giraffe and special treatment (birthday crown, store announcement, Geoffrey balloon) at the store on the day of. Sign up here for the rewards program.

Au Bon Pain gives you a free lunch (choice of any sandwich or salad) for your birthday when you sign up for their e-club. They also send $1 off coupons pretty regularly with their e-newsletters.
Chipotle used to do a free burrito for your b-day if you showed your driver's license to the manager. It's not advertised, but most locations will do it :)